4results about How to "Reduce brazing temperature" patented technology

The invention provides a titanium alloy current-assisted vacuum brazing tool and process method. The titanium alloy current-assisted vacuum brazing tool and process method comprises the steps that S1, a titanium alloy columnar body to be welded is machined; s2, TiZrCuNi brazing filler metal alloy powder is adopted for preparing a brazing middle layer; s3, polishing the welding surface of the titanium alloy cylindrical body to be welded; s4, the welding face of one to-be-welded titanium alloy base material is placed upwards, brazing filler metal alloy powder of a brazing middle layer is evenly spread, the welding face of the other titanium alloy base material is placed above the middle layer downwards, and a three-layer structure is formed; s5, a workpiece to be welded and a thermocouple are inserted into a titanium alloy current auxiliary vacuum brazing tool and then placed in a vacuum hot-pressing brazing furnace, graphite cushion blocks are arranged at the top of the upper-layer base metal and the bottom of the lower-layer base metal correspondingly, and an electrode pressing head makes contact with the graphite cushion blocks at the top of the upper-layer base metal; and S6, titanium alloy current auxiliary vacuum brazing is conducted. According to the method, the workpiece is rapidly and uniformly heated in a heating and current applying mode, and the titanium alloy brazed joint which is good in bonding strength and excellent in performance is prepared.

This invention proposes a brazing method for aluminum alloys based on surface activation and a pre-placed Ni layer. The method includes: Step 1, pre-treating the aluminum alloy surface to be brazed to ensure it is dust-free and oil-free; Step 2, subjecting the aluminum alloy surface to ion bombardment to remove the oxide film and activate the surface; Step 3, depositing a Ni thin film on the aluminum alloy surface to form a pre-placed Ni layer; Step 4, assembling the aluminum alloys to be brazed and placing them in a vacuum brazing furnace, with the Ni layers of the two aluminum alloys in contact. Pressure is applied to ensure the upper and lower aluminum alloys are tightly bonded and to prevent relative sliding. The furnace is then vacuum-heated to 540℃~585℃ and held for a preset time before cooling to room temperature to obtain an aluminum alloy / Ni / aluminum alloy brazed joint. The joint obtained by this surface-activated, pre-placed Ni layer-based aluminum alloy brazing method has the characteristics of no oxide film at the interface, high tensile strength, and low deformation rate.

The invention discloses a strontium titanate ceramic low-temperature brazing connection method, and particularly relates to the field of ceramic brazing. The preparation method of the glass powder comprises the following steps: mixing the V2O5 powder, the B2O3 powder, the Al2O3 powder and the CaO powder according to the mass fraction to obtain mixed powder; and heating the mixed powder to obtain molten glass, and preparing the molten glass into glass powder. Mixing the glass powder with a binder to obtain the glass soldering paste; the to-be-welded face of the strontium titanate ceramic is coated with the glass soldering paste, and the to-be-welded strontium titanate ceramic is obtained; two strontium titanate ceramics to be welded are placed in a laminated mode, and a strontium titanate ceramic-glass soldering paste-strontium titanate ceramic sandwich structure is obtained to serve as a piece to be welded; and heating the to-be-welded part to obtain the brazed strontium titanate ceramic. The vanadate glass powder serves as brazing filler metal, the thermal expansion coefficient of the vanadate glass powder is matched with that of strontium titanate ceramic, the brazing temperature is low, and therefore the residual stress of a connector can be effectively reduced, and the strength of the connector is improved.

This application discloses a method for preparing a powder-rolled brazing plate for low-temperature brazing, comprising: preparing alloy powder; preparing an aluminum alloy shell, and loading the alloy powder into the aluminum alloy shell; performing hot isostatic pressing and hot rolling to obtain the brazing plate; wherein the mass percentage of the alloy powder is: Si 6-12.5%, Cu 1.8-10%, Zn 3.8-20%, Fe 0.1-1.1%, with the balance being aluminum; the thickness of the aluminum alloy shell is 10-20 mm. This method can reduce the brazing temperature of the product, achieving brazing at 530-550℃ with excellent brazing results.